Self-hosted server for Protonmail client.

Demo: http://neutron.emersion.fr (username: neutron, passwords: neutron)

Keep in mind that Neutron is less secure than ProtonMail: most servers don't use full-disk encryption and aren't under 1,000 meters of granite rock in Switzerland. If you use Neutron, make sure to donate to ProtonMail!

The initial goal is to support IMAP & SMTP servers (authentication, messages and folders), storing everything else (contacts & settings) on disk. Neutron is modular so it's easy to create new backends and handle more scenarios.

• Debian & Ubuntu: install from https://packager.io/gh/emersion/neutron and run with neutronmail run web
• Other platforms: no packages yet, you'll have to build from source

• -config: specify a custom config file
• -help: show help

See config.json.

{
	"Memory": {
		"Enabled": true,
		"Populate": false,
		"Domains": ["emersion.fr"] // Available e-mail domains
	},
	"Imap": { // IMAP server config
		"Enabled": true,
		"Hostname": "mail.gandi.net",
		"Suffix": "@emersion.fr"
	},
	"Smtp": { // SMTP server config
		"Enabled": true,
		"Hostname": "mail.gandi.net",
		"Port": 587,
		"Suffix": "@emersion.fr"
	},
	"Disk": { // Store keys, contacts and settings on disk
		"Enabled": true,
		"Keys": { "Directory": "keys" },
		"Contacts": { "Directory": "contacts" },
		"UsersSettings": { "Directory": "users" }
	}
}

To add a new user, just click Sign up on the login page and enter your IMAP credentials.

One field per backend, each one containing a boolean Enabled to turn it on or off.

• Memory: stores all data in memory. Set Populate to true to automatically populate memory with some data (username: neutron, passwords: neutron).
• Imap: stores messages on an IMAP server
• Smtp: sends messages via a SMTP server
• Disk: store all data on disk

Requirements:

• Go (to build the server)
• Node, NPM (to build the client)

# Get the code
go get -u github.com/emersion/neutron
cd $GOPATH/src/github.com/emersion/neutron

# Build the client
git submodule init
git submodule update
make build-client

# Start the server
make start

All backends must implement the backend interface. The main backend interface is split into multiple other backend interfaces for different roles: ContactsBackend, LabelsBackend and so on. This allows to build modular backends, e.g. a MessagesBackend which stores messages on an IMAP server with a ContactsBackend which stores contacts on a LDAP server and a SendBackend which sends outgoing messages to a SMTP server.

Writing a backend is just a matter of implementing the necessary functions. You can read the memory backend to understand how to do that. Docs for the backend are available here: https://godoc.org/github.com/emersion/neutron/backend#Backend

MIT